package com.mmall.concurrency.example.atomic;

import com.mmall.concurrency.annoations.ThreadSafe;
import com.mmall.concurrency.example.commonunsafe.ArrayListExample;

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.atomic.AtomicInteger;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 模拟并发，需要用到信号量来模拟同时200个并发，用CountDownLatch来模拟计数，一共有多少个请求
 */
@Slf4j
@ThreadSafe
public class AtomicExample1 {
	private static Logger log = LoggerFactory.getLogger(ArrayListExample.class);

    // 请求总数
    public static int clientTotal = 5000;

    // 同时并发执行的线程数
    public static int threadTotal = 200;

    public static AtomicInteger count = new AtomicInteger(0);

    public static void main(String[] args) throws Exception{
        ExecutorService executorService = Executors.newCachedThreadPool();
        final Semaphore semaphore = new Semaphore(threadTotal);
        final CountDownLatch countDownLatch = new CountDownLatch(clientTotal);
        for (int i = 0; i < clientTotal; i++) {
            executorService.execute(()->{
                try {
                    semaphore.acquire();
                    add();
                    semaphore.release();
                }catch (Exception e){
                    log.error("exception", e);
                }
                countDownLatch.countDown();
            });
        }
        countDownLatch.await(); // 阻塞main线程，直到所有的线程都执行并完成计数
        log.info("count:{}",count.get());

    }

    private static void add(){
        count.incrementAndGet();
//        count.getAndIncrement();
    }
}
